Golf ball core

ABSTRACT

A golf ball with a center core comprising 1,4 polybutadiene with a cis content more than 50% and containing a metal salt of acrylate, wherein the 1,4 polybutadiene has 5 to 60 weight percent of a metal salt of acrylate, is disclosed herein. The metal salt of acrylate is preferably selected from zinc, magnesium, sodium, and calcium.

CROSS REFERENCES TO RELATED APPLICATIONS

The Present Application is a continuation application of U.S. patentapplication Ser. No. 16/925,748, filed on Jul. 10, 2020, which is acontinuation application of U.S. patent application Ser. No. 16/361,470,filed on Mar. 22, 2019, now U.S. patent Ser. No. 10/709,937, issued onJul. 14, 2020, which claims priority to U.S. Provisional patentApplication No. 62/648,811, filed Mar. 27, 2018, each of which is herebyincorporated by reference in its entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

BACKGROUND OF THE INVENTION Field of the Invention

The present invention generally relates to golf ball core materials,specifically polybutadiene materials.

Description of the Related Art

Various types of unsaturated polymeric materials, such as elastomers andrubbers, have been used in golf balls with the utilization of thosemechanical properties developed by the crosslinking of unsaturation withthermo/chemical curing or irradiation. One representative example is agolf ball core, which is obtained mainly from crosslinked polybutadienewith sulfur compounds, or peroxides together with ZnO and metal salt ofacrylate, such as ZDA or ZDMA.

Depending on the design of the golf ball, core compression can beadjusted to get a desired ball performance. It is generally known thatincreasing the loading level of metal salt of acrylates increases corecompression and COR. The most preferred metal cation used for coreapplication is zinc (zinc diacrylate). High loading of zinc diacrylateis required to obtain sufficient core compression and COR and thephysical properties can be inconsistent if the zinc diacrylate is notfinely dispersed in the polybutadiene matrix.

BRIEF SUMMARY OF THE INVENTION

In this invention, various metal salts of acrylate are chemicallyattached to the main chain of polybutadiene during the synthesizingprocess. Since metal salt of acrylate is already incorporated into thepolybutadiene structure, more consistent physical properties areobtained. Various metal cations such as Zn, Mg, Na, and Ca result invarying synergistic effects on the physical properties of the core,especially the COR.

Having briefly described the present invention, the above and furtherobjects, features and advantages thereof will be recognized by thoseskilled in the pertinent art from the following detailed description ofthe invention when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is an exploded partial cut-away view of a golf ball.

FIG. 2 is top perspective view of a golf ball.

FIG. 3 is a cross-sectional view of a core component of a golf ball.

FIG. 4 is a cross-sectional view of a core component and a mantlecomponent of a golf ball.

FIG. 5 is a cross-sectional view of an inner core layer, an outer corelayer, an inner mantle layer, an outer mantle layer and a cover layer ofa golf ball.

FIG. 5A is a cross-sectional view of an inner core layer, anintermediate core layer, an outer core layer, a mantle layer and a coverlayer of a golf ball.

FIG. 6 is a cross-sectional view of an inner core layer under a 100kilogram load.

FIG. 7 is a cross-sectional view of a core under a 100 kilogram load.

FIG. 8 is a cross-sectional view of a core component and a mantlecomponent of a golf ball.

FIG. 9 is a cross-sectional view of a core component, the mantlecomponent and a cover layer of a golf ball.

FIG. 10 is an exploded partial cut-away view of a four-piece golf ball.

FIG. 11 is an exploded partial cut-away view of a three-piece golf ball.

FIG. 12 is an exploded partial cut-away view of a two-piece golf ball.

FIG. 13 is a cross-sectional view of a two-piece golf ball.

FIG. 14 is a cross-sectional view of a three-piece golf ball.

FIG. 15 is an exploded partial cut-away view of a three-piece golf ball.

FIG. 16 is a cross-sectional view of a three-piece golf ball with a dualcore and a cover.

FIG. 17 is a cross-sectional view of a three-piece golf ball with acore, mantle and cover.

FIG. 18 is a cross-sectional view of a four-piece golf ball with a dualcore, mantle layer and a cover.

FIG. 19 is a cross-sectional view of a four-piece golf ball with a core,dual mantle layers and a cover.

DETAILED DESCRIPTION OF THE INVENTION

The polybutadiene matrix of the present invention increases theconsistency of physical properties.

The polybutadiene matrix of the present invention increases the CORusing mixture of metal cations.

The polybutadiene matrix of the present invention lowers themanufacturing cost by reducing kneading time.

The golf ball core preferably has a composition comprising: 1,4polybutadiene with a cis content more than 50% and containing a metalsalt of acrylate, wherein the 1,4 polybutadiene has 5 to 60 weight % ofmetal salt of acrylate. The preferred metal cations for metal salt ofacrylate are zinc, magnesium, sodium, and calcium. Two or more differentmetal cations of metal salt of acrylate may be used.

The core composition in this invention contains free radical formerssuch as sulfur, azo compound, organic peroxide or combination of thosewith or without the presence of co-crosslinking agent, such as ZnO andZD(M)A. The core composition further contains peptizers, accelerators,inhibitors, activators, colorants, foaming agents, and organic,inorganic or metallic fillers or fibers. The mixing methods includeusing two-roll mill, a banbury mixer, or an extruder. The composition ispreferably crosslinked by any conventional crosslinking method(s), suchas by applying thermal energy, irradiation, and combination of those.

FIGS. 1, 3, 4 and 5 illustrate a five piece golf ball 10 comprising aninner core 12 a, an outer core 12 b, an inner mantle 14 a, an outermantle 14 b, and a cover 16, wherein the inner core is composed of apolybutadiene matrix comprising a metal salt of acrylate, wherein the1,4 polybutadiene matrix has 5 to 60 weight percent of the metal salt ofacrylate.

FIG. 5A illustrates a five piece golf ball 10 comprising an inner core12 a, an intermediate core 12 b, an outer core 12 c, a mantle 14, and acover 16, wherein the inner core is composed of a polybutadiene matrixcomprising a metal salt of acrylate, wherein the 1,4 polybutadienematrix has 5 to 60 weight percent of the metal salt of acrylate.

FIGS. 8 and 9 illustrate a six piece golf ball 10 comprising an innercore 12 a, an intermediate core 12 b, an outer core 12 c, an innermantle 14 a, an outer mantle 14 b, and a cover 16, wherein the innercore is composed of a polybutadiene matrix comprising a metal salt ofacrylate, wherein the 1,4 polybutadiene matrix has 5 to 60 weightpercent of the metal salt of acrylate.

FIG. 10 illustrates a four piece golf ball comprising a dual core, aboundary layer and a cover, wherein the inner core is composed of apolybutadiene matrix comprising a metal salt of acrylate, wherein the1,4 polybutadiene matrix has 5 to 60 weight percent of the metal salt ofacrylate.

FIG. 11 illustrates a three piece golf ball comprising a core, aboundary layer and a cover, wherein the inner core is composed of apolybutadiene matrix comprising a metal salt of acrylate, wherein the1,4 polybutadiene matrix has 5 to 60 weight percent of the metal salt ofacrylate.

FIGS. 12 and 13 illustrate a two piece golf ball 20 with a core 25 and acover 30, wherein the inner core is composed of a polybutadiene matrixcomprising a metal salt of acrylate, wherein the 1,4 polybutadienematrix has 5 to 60 weight percent of the metal salt of acrylate.

FIGS. 14 and 15 illustrate a three-piece golf ball 5 comprising a core10, a mantle layer 14 and a cover 16 with dimples 18, wherein the innercore is composed of a polybutadiene matrix comprising a metal salt ofacrylate, wherein the 1,4 polybutadiene matrix has 5 to 60 weightpercent of the metal salt of acrylate.

FIG. 16 illustrates a dual core three piece golf ball 35 comprising aninner core 30, and outer core 32 and a cover 34, wherein the inner coreis composed of a polybutadiene matrix comprising a metal salt ofacrylate, wherein the 1,4 polybutadiene matrix has 5 to 60 weightpercent of the metal salt of acrylate.

FIG. 17 illustrates a three piece golf ball 45 comprising a core 40, amantle layer 42 and a cover 44, wherein the inner core is composed of apolybutadiene matrix comprising a metal salt of acrylate, wherein the1,4 polybutadiene matrix has 5 to 60 weight percent of the metal salt ofacrylate.

FIG. 18 illustrates a dual core four piece golf ball 55 comprising aninner core 50, an outer core 52, a mantle layer 54 and a cover 56,wherein the inner core is composed of a polybutadiene matrix comprisinga metal salt of acrylate, wherein the 1,4 polybutadiene matrix has 5 to60 weight percent of the metal salt of acrylate.

FIG. 19 illustrates a four piece golf ball 65 comprising a core 60, aninner mantle 62, an outer mantle 64 and a cover 66, wherein the innercore is composed of a polybutadiene matrix comprising a metal salt ofacrylate, wherein the 1,4 polybutadiene matrix has 5 to 60 weightpercent of the metal salt of acrylate.

The mantle component is preferably composed of the inner mantle layerand the outer mantle layer. The mantle component preferably has athickness ranging from 0.05 inch to 0.15 inch, and more preferably from0.06 inch to 0.08 inch. The outer mantle layer is preferably composed ofa blend of ionomer materials. One preferred embodiment comprises SURLYN9150 material, SURLYN 8940 material, a SURLYN AD1022 material, and amasterbatch. The SURLYN 9150 material is preferably present in an amountranging from 20 to 45 weight percent of the cover, and more preferably30 to 40 weight percent. The SURLYN 8945 is preferably present in anamount ranging from 15 to 35 weight percent of the cover, morepreferably 20 to 30 weight percent, and most preferably 26 weightpercent. The SURLYN 9945 is preferably present in an amount ranging from30 to 50 weight percent of the cover, more preferably 35 to 45 weightpercent, and most preferably 41 weight percent. The SURLYN 8940 ispreferably present in an amount ranging from 5 to 15 weight percent ofthe cover, more preferably 7 to 12 weight percent, and most preferably10 weight percent.

SURLYN 8320, from DuPont, is a very-low modulus ethylene/methacrylicacid copolymer with partial neutralization of the acid groups withsodium ions. SURLYN 8945, also from DuPont, is a high acidethylene/methacrylic acid copolymer with partial neutralization of theacid groups with sodium ions. SURLYN 9945, also from DuPont, is a highacid ethylene/methacrylic acid copolymer with partial neutralization ofthe acid groups with zinc ions. SURLYN 8940, also from DuPont, is anethylene/methacrylic acid copolymer with partial neutralization of theacid groups with sodium ions.

The inner mantle layer is preferably composed of a blend of ionomers,preferably comprising a terpolymer and at least two high acid (greaterthan 18 weight percent) ionomers neutralized with sodium, zinc,magnesium, or other metal ions. The material for the inner mantle layerpreferably has a Shore D plaque hardness ranging preferably from 35 to77, more preferably from 36 to 44, a most preferably approximately 40.The thickness of the outer mantle layer preferably ranges from 0.025inch to 0.050 inch, and is more preferably approximately 0.037 inch. Themass of an insert including the dual core and the inner mantle layerpreferably ranges from 32 grams to 40 grams, more preferably from 34 to38 grams, and is most preferably approximately 36 grams. The innermantle layer is alternatively composed of a HPF material available fromDuPont. Alternatively, the inner mantle layer 14 b is composed of amaterial such as disclosed in Kennedy, III et al., U.S. Pat. No.7,361,101 for a Golf Ball And Thermoplastic Material, which is herebyincorporated by reference in its entirety.

The outer mantle layer is preferably composed of a blend of ionomers,preferably comprising at least two high acid (greater than 18 weightpercent) ionomers neutralized with sodium, zinc, or other metal ions.The blend of ionomers also preferably includes a masterbatch. Thematerial of the outer mantle layer preferably has a Shore D plaquehardness ranging preferably from 55 to 75, more preferably from 65 to71, and most preferably approximately 67. The thickness of the outermantle layer preferably ranges from 0.025 inch to 0.040 inch, and ismore preferably approximately 0.030 inch. The mass of the entire insertincluding the core, the inner mantle layer and the outer mantle layerpreferably ranges from 38 grams to 43 grams, more preferably from 39 to41 grams, and is most preferably approximately 41 grams.

In an alternative embodiment, the inner mantle layer is preferablycomposed of a blend of ionomers, preferably comprising at least two highacid (greater than 18 weight percent) ionomers neutralized with sodium,zinc, or other metal ions. The blend of ionomers also preferablyincludes a masterbatch. In this embodiment, the material of the innermantle layer has a Shore D plaque hardness ranging preferably from 55 to75, more preferably from 65 to 71, and most preferably approximately 67.The thickness of the outer mantle layer preferably ranges from 0.025inch to 0.040 inch, and is more preferably approximately 0.030 inch.Also in this embodiment, the outer mantle layer 14 b is composed of ablend of ionomers, preferably comprising a terpolymer and at least twohigh acid (greater than 18 weight percent) ionomers neutralized withsodium, zinc, magnesium, or other metal ions. In this embodiment, thematerial for the outer mantle layer 14 b preferably has a Shore D plaquehardness ranging preferably from 35 to 77, more preferably from 36 to44, a most preferably approximately 40. The thickness of the outermantle layer preferably ranges from 0.025 inch to 0.100 inch, and morepreferably ranges from 0.070 inch to 0.090 inch.

In yet another embodiment wherein the inner mantle layer is thicker thanthe outer mantle layer and the outer mantle layer is harder than theinner mantle layer, the inner mantle layer is composed of a blend ofionomers, preferably comprising a terpolymer and at least two high acid(greater than 18 weight percent) ionomers neutralized with sodium, zinc,magnesium, or other metal ions. In this embodiment, the material for theinner mantle layer has a Shore D plaque hardness ranging preferably from30 to 77, more preferably from 30 to 50, and most preferablyapproximately 40. In this embodiment, the material for the outer mantlelayer has a Shore D plaque hardness ranging preferably from 40 to 77,more preferably from 50 to 71, and most preferably approximately 67. Inthis embodiment, the thickness of the inner mantle layer preferablyranges from 0.030 inch to 0.090 inch, and the thickness of the outermantle layer ranges from 0.025 inch to 0.070 inch.

Preferably the inner core has a diameter ranging from 0.75 inch to 1.20inches, more preferably from 0.85 inch to 1.05 inch, and most preferablyapproximately 0.95 inch. Preferably the inner core 12 a has a Shore Dhardness ranging from 20 to 50, more preferably from 25 to 40, and mostpreferably approximately 35. Preferably the inner core is formed fromTPEE composed of short chain glycols. Preferably the inner core has amass ranging from 5 grams to 15 grams, 7 grams to 10 grams and mostpreferably approximately 8 grams.

Preferably the outer core has a diameter ranging from 1.25 inch to 1.55inches, more preferably from 1.40 inch to 1.5 inch, and most preferablyapproximately 1.5 inch. Preferably the outer core has a Shore D surfacehardness ranging from 40 to 65, more preferably from 50 to 60, and mostpreferably approximately 56. Preferably the outer core is formed from apolybutadiene, zinc diacrylate, zinc oxide, zinc stearate, a peptizerand peroxide. Preferably the combined inner core and outer core have amass ranging from 25 grams to 35 grams, 30 grams to 34 grams and mostpreferably approximately 32 grams.

Preferably the inner core has a deflection of at least 0.230 inch undera load of 220 pounds, and the core has a deflection of at least 0.080inch under a load of 200 pounds. As shown in FIGS. 6 and 7, a mass 50 isloaded onto an inner core and a core. As shown in FIGS. 6 and 7, themass is 100 kilograms, approximately 220 pounds. Under a load of 100kilograms, the inner core preferably has a deflection from 0.230 inch to0.300 inch. Under a load of 100 kilograms, preferably the core has adeflection of 0.08 inch to 0.150 inch. Alternatively, the load is 200pounds (approximately 90 kilograms), and the deflection of the core 12is at least 0.080 inch. Further, a compressive deformation from abeginning load of 10 kilograms to an ending load of 130 kilograms forthe inner core ranges from 4 millimeters to 7 millimeters and morepreferably from 5 millimeters to 6.5 millimeters. The dual coredeflection differential allows for low spin off the tee to providegreater distance, and high spin on approach shots.

In an alternative embodiment of the golf ball shown in FIG. 5A, the golfball 10 comprises an inner core 12 a, an intermediate core 12 b, anouter core 12 b, a mantle 14 and a cover 16. The golf ball 10 preferablyhas a diameter of at least 1.68 inches, a mass ranging from 45 grams to47 grams, a COR of at least 0.79, a deformation under a 100 kilogramloading of at least 0.07 mm.

In one embodiment, the golf ball comprises a core, a mantle layer and acover layer. The core comprises an inner core sphere, an intermediatecore layer and an outer core layer. The inner core sphere comprises aTPEE material and has a diameter ranging from 0.875 inch to 1.4 inches.The intermediate core layer is composed of a highly neutralized ionomerand has a Shore D hardness less than 40. The outer core layer iscomposed of a highly neutralized ionomer and has a Shore D hardness lessthan 45. A thickness of the intermediate core layer is greater than athickness of the outer core layer. The mantle layer is disposed over thecore, comprises an ionomer material and has a Shore D hardness greaterthan 55. The cover layer is disposed over the mantle layer comprises athermoplastic polyurethane material and has a Shore A hardness less than100. The golf ball has a diameter of at least 1.68 inches. The mantlelayer is harder than the outer core layer, the outer core layer isharder than the intermediate core layer, the intermediate core layer isharder than the inner core sphere, and the cover layer is softer thanthe mantle layer.

In another embodiment, shown in FIGS. 8 and 9, the golf ball 10 has amulti-layer core and multi-layer mantle. The golf ball includes a core,a mantle component and a cover layer. The core comprises an inner coresphere, an intermediate core layer and an outer core layer. The innercore sphere comprises a TPEE material and has a diameter ranging from0.875 inch to 1.4 inches. The intermediate core layer is composed of ahighly neutralized ionomer and has a Shore D hardness less than 40. Theouter core layer is composed of a highly neutralized ionomer and has aShore D hardness less than 45. A thickness of the intermediate corelayer is greater than a thickness of the outer core layer 12 c. Theinner mantle layer is disposed over the core, comprises an ionomermaterial and has a Shore D hardness greater than 55. The outer mantlelayer is disposed over the inner mantle layer, comprises an ionomermaterial and has a Shore D hardness greater than 60. The cover layer isdisposed over the mantle component, comprises a thermoplasticpolyurethane material and has a Shore A hardness less than 100. The golfball has a diameter of at least 1.68 inches. The outer mantle layer isharder than the inner mantle layer, the inner mantle layer is harderthan the outer core layer, the outer core layer is harder than theintermediate core layer, the intermediate core layer is harder than theinner core sphere, and the cover layer is softer than the outer mantlelayer.

In a particularly preferred embodiment of the invention, the golf ballpreferably has an aerodynamic pattern such as disclosed in Simonds etal., U.S. Pat. No. 7,419,443 for a Low Volume Cover For A Golf Ball,which is hereby incorporated by reference in its entirety.Alternatively, the golf ball has an aerodynamic pattern such asdisclosed in Simonds et al., U.S. Pat. No. 7,338,392 for An AerodynamicSurface Geometry For A Golf Ball, which is hereby incorporated byreference in its entirety.

Various aspects of the present invention golf balls have been describedin terms of certain tests or measuring procedures. These are describedin greater detail as follows.

As used herein, “Shore D hardness” of the golf ball layers is measuredgenerally in accordance with ASTM D-2240 type D, except the measurementsmay be made on the curved surface of a component of the golf ball,rather than on a plaque. If measured on the ball, the measurement willindicate that the measurement was made on the ball. In referring to ahardness of a material of a layer of the golf ball, the measurement willbe made on a plaque in accordance with ASTM D-2240. Furthermore, theShore D hardness of the cover is measured while the cover remains overthe mantles and cores. When a hardness measurement is made on the golfball, the Shore D hardness is preferably measured at a land area of thecover.

As used herein, “Shore A hardness” of a cover is measured generally inaccordance with ASTM D-2240 type A, except the measurements may be madeon the curved surface of a component of the golf ball, rather than on aplaque. If measured on the ball, the measurement will indicate that themeasurement was made on the ball. In referring to a hardness of amaterial of a layer of the golf ball, the measurement will be made on aplaque in accordance with ASTM D-2240. Furthermore, the Shore A hardnessof the cover is measured while the cover remains over the mantles andcores. When a hardness measurement is made on the golf ball, Shore Ahardness is preferably measured at a land area of the cover

The resilience or coefficient of restitution (COR) of a golf ball is theconstant “e,” which is the ratio of the relative velocity of an elasticsphere after direct impact to that before impact. As a result, the COR(“e”) can vary from 0 to 1, with 1 being equivalent to a perfectly orcompletely elastic collision and 0 being equivalent to a perfectly orcompletely inelastic collision.

COR, along with additional factors such as club head speed, club headmass, ball weight, ball size and density, spin rate, angle of trajectoryand surface configuration as well as environmental conditions (e.g.temperature, moisture, atmospheric pressure, wind, etc.) generallydetermine the distance a ball will travel when hit. Along this line, thedistance a golf ball will travel under controlled environmentalconditions is a function of the speed and mass of the club and size,density and resilience (COR) of the ball and other factors. The initialvelocity of the club, the mass of the club and the angle of the ball'sdeparture are essentially provided by the golfer upon striking. Sinceclub head speed, club head mass, the angle of trajectory andenvironmental conditions are not determinants controllable by golf ballproducers and the ball size and weight are set by the U.S.G.A., theseare not factors of concern among golf ball manufacturers. The factors ordeterminants of interest with respect to improved distance are generallythe COR and the surface configuration of the ball.

The coefficient of restitution is the ratio of the outgoing velocity tothe incoming velocity. In the examples of this application, thecoefficient of restitution of a golf ball was measured by propelling aball horizontally at a speed of 125+/−5 feet per second (fps) andcorrected to 125 fps against a generally vertical, hard, flat steelplate and measuring the ball's incoming and outgoing velocityelectronically. Speeds were measured with a pair of ballistic screens,which provide a timing pulse when an object passes through them. Thescreens were separated by 36 inches and are located 25.25 inches and61.25 inches from the rebound wall. The ball speed was measured bytiming the pulses from screen 1 to screen 2 on the way into the reboundwall (as the average speed of the ball over 36 inches), and then theexit speed was timed from screen 2 to screen 1 over the same distance.The rebound wall was tilted 2 degrees from a vertical plane to allow theball to rebound slightly downward in order to miss the edge of thecannon that fired it. The rebound wall is solid steel.

As indicated above, the incoming speed should be 125±5 fps but correctedto 125 fps. The correlation between COR and forward or incoming speedhas been studied and a correction has been made over the ±5 fps range sothat the COR is reported as if the ball had an incoming speed of exactly125.0 fps.

The measurements for deflection, compression, hardness, and the like arepreferably performed on a finished golf ball as opposed to performingthe measurement on each layer during manufacturing.

Preferably, in a five layer golf ball comprising an inner core, an outercore, an inner mantle layer, an outer mantle layer and a cover, thehardness/compression of layers involve an inner core with the greatestdeflection (lowest hardness), an outer core (combined with the innercore) with a deflection less than the inner core, an inner mantle layerwith a hardness less than the hardness of the combined outer core andinner core, an outer mantle layer with the hardness layer of the golfball, and a cover with a hardness less than the hardness of the outermantle layer. These measurements are preferably made on a finished golfball that has been torn down for the measurements.

Preferably the inner mantle layer is thicker than the outer mantle layeror the cover layer. The dual core and dual mantle golf ball creates anoptimized velocity-initial velocity ratio (Vi/IV), and allows for spinmanipulation. The dual core provides for increased core compressiondifferential resulting in a high spin for short game shots and a lowspin for driver shots. A discussion of the USGA initial velocity test isdisclosed in Yagley et al., U.S. Pat. No. 6,595,872 for a Golf Ball WithHigh Coefficient Of Restitution, which is hereby incorporated byreference in its entirety. Another example is Bartels et al., U.S. Pat.No. 6,648,775 for a Golf Ball With High Coefficient Of Restitution,which is hereby incorporated by reference in its entirety.

Alternatively, the cover 16 is composed of a thermoplasticpolyurethane/polyurea material. One example is disclosed in U.S. Pat.No. 7,367,903 for a Golf Ball, which is hereby incorporated by referencein its entirety. Another example is Melanson, U.S. Pat. No. 7,641,841,which is hereby incorporated by reference in its entirety. Anotherexample is Melanson et al, U.S. Pat. No. 7,842,211, which is herebyincorporated by reference in its entirety. Another example is Matroni etal., U.S. Pat. No. 7,867,111, which is hereby incorporated by referencein its entirety. Another example is Dewanjee et al., U.S. Pat. No.7,785,522, which is hereby incorporated by reference in its entirety.

Bartels, U.S. Pat. No. 9,278,260, for a Low Compression Three-Piece GolfBall With An Aerodynamic Drag Rise At High Speeds, is herebyincorporated by reference in its entirety.

Chavan et al, U.S. Pat. No. 9,789,366, for a Graphene Core For A GolfBall, is hereby incorporated by reference in its entirety.

Chavan et al, U.S. patent application Ser. No. 15/705,011, filed on Sep.14, 2017, for a Graphene Core For A Golf Ball, is hereby incorporated byreference in its entirety.

Chavan et al, U.S. patent application Ser. No. 15/729,231, filed on Oct.10, 2017, for a Graphene And Nanotube Reinforced Golf Ball, is herebyincorporated by reference in its entirety.

Brown, U.S. patent application Ser. No. 15/683,398, filed on Aug. 22,2017, for a Golf Ball With Improved Durability, is hereby incorporatedby reference in its entirety.

Crast et al., U.S. Pat. No. 6,632,877, for a Dual Curable Coating, ishereby incorporated by reference in its entirety.

Skrabski et al., U.S. Pat. No. 6,544,337, for a Golf ball PaintingSystem, is hereby incorporated by reference in its entirety.

Crast et al., U.S. Pat. No. 6,365,679, for a Two component polyurethaneclear coat for golf balls, is hereby incorporated by reference in itsentirety.

Crast et al., U.S. Pat. No. 6,165,564, for a UV Clearable Clear Coat ForGolf Balls, is hereby incorporated by reference in its entirety.

Skrabski et al., U.S. Pat. No. 6,319,563, for a Golf ball PaintingMethod, is hereby incorporated by reference in its entirety.

Matroni et al., U.S. Pat. No. 7,485,052, for a Golf Ball, is herebyincorporated by reference in its entirety.

From the foregoing it is believed that those skilled in the pertinentart will recognize the meritorious advancement of this invention andwill readily understand that while the present invention has beendescribed in association with a preferred embodiment thereof, and otherembodiments illustrated in the accompanying drawings, numerous changes,modifications and substitutions of equivalents may be made thereinwithout departing from the spirit and scope of this invention which isintended to be unlimited by the foregoing except as may appear in thefollowing appended claims. Therefore, the embodiments of the inventionin which an exclusive property or privilege is claimed are defined inthe following appended claims.

I claim as my invention the following:
 1. A golf ball comprising: a coreformed from a mixture comprising 1,4 polybutadiene with a cis contentmore than 50% and containing a metal salt of acrylate, wherein the 1,4polybutadiene has 5 to 60 weight percent of a metal salt of acrylatechemically attached to a main chain of the 1, 4 polybutadiene, 0.4 to2.5 weight percent graphene material, 1-30 weight percent polyisoprene,10-50 weight percent zinc diacrylate, 1-30 weight percent zinc oxide,1-20 weight percent zinc stearate, and 0.1-10 weight percent peroxideinitiator; an inner mantle disposed over the core; an outer mantledisposed over the inner mantle; a cover layer disposed over the outermantle.
 2. The golf ball according to claim 1 wherein metal salt ofacrylate are zinc, magnesium, sodium, and calcium.
 3. The golf ballaccording to claim 1 wherein the cover layer has a thickness rangingfrom 0.025 inch to 0.045 inch.
 4. The golf ball according to claim 1wherein the cover layer is formed of a TPU.